[1] Please draw an ERD based on following description.

The BusyBee Cleaning Company specializes in providing cleaning services for both domestic and commercial clients. Each type of client has a set of requirements. For example, The Cardboard Box Company requires cleaning services from Monday to Friday 7am until 9am and 5pm until 7pm each day, but P. Nuttall only requires cleaning services on a Wednesday from 10am until 1pm.

Whenever a new client is taken on, a BusyBee administrator assesses how many cleaning staff are required for the premises prior to assigning any staff to the job. Note that this is the ideal number, it may differ in practice. In addition, the administrator also assesses whether any specialist equipment is required and when. For example, three industrial floor cleaners may be needed on two out of five occasions for one commercial client.

The cleaning staff work in groups of six, with a supervisor to oversee the work done. The other staff are administrative staff who manage the day-to-day office work including visiting new clients and ensuring the specialist equipment is properly maintained.